Stranded by the nationwide slump in housing and jobs, fewer Americans are moving, the Census Bureau said Wednesday.

The bureau found that the number of people who changed residences declined to 35.2 million from March 2007 to March 2008, the lowest number since 1962, when the nation had 120 million fewer people.

Experts said the lack of mobility was of concern on two fronts. It suggests that Americans were unable or unwilling to follow any job opportunities that may have existed around the country, as they have in the past. And the lack of movement itself, they said, could have an impact on the economy, reducing the economic activity generated by moves.

Joseph S. Tracy, research director of the Federal Reserve Bank of New York, said the lack of mobility meant less income for movers and the people they employ and less spending on renovation and on durable goods like appliances. But, Dr. Tracy said, the most troubling prospect is that people were no longer able to relocate for work.

“The thing that would be of deeper concern is if job-related moves are getting suppressed and workers are not getting re-sorted to the jobs that best use their skills,” he said. “As the labor market started to improve, if mobility stays low, you can worry about the allocation of workers.”

How long will the downturn in mobility last? Michael J. Hicks, director of the Center for Business and Economic Research at Ball State University in Indiana, said, “I think it will be well into next year before we see any growth in migration, and that still may be optimistic.”

“If the stock market rebounds before the housing market, we might see a scramble for retirement housing,” Professor Hicks added.